[pan] fix YAML syntax in .gitlab-ci.yml

[Dominique Dumont <ddumont src gnome org>]

commit 1b96a807cca74f932523b97da365a4969baa1139
Author: Dominique Dumont <dod debian org>
Date:   Mon Jan 10 19:52:31 2022 +0100

    fix YAML syntax in .gitlab-ci.yml

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a06f30b..e3bf360 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -11,6 +11,7 @@ build-ubuntu-gtk2:
     - tags
   before_script:
     - apt-get update
+     # libgtk-3-dev is required by make distcheck step
     - apt-get install -q -y --no-install-recommends
         build-essential
         autoconf
@@ -19,7 +20,7 @@ build-ubuntu-gtk2:
         gettext
         gcc
         libgtk2.0-dev
-        libgtk-3-dev # required by make distcheck
+        libgtk-3-dev
         libgmime-3.0-dev
         libnotify-dev
         gnome-keyring